A Russian Rokot/Briz KM launch vehicle orbited three Gonets 3M data relay satellites and
an unidentified military satellite identified as Cosmos 2499 from Area 133 Pad 3 at
Plesetsk space center on March 31, 2015. The three stage rocket lifted off at 13:48 UTC.
Its Briz-KM third stage performed two burns to lift the three 282 kg Gonets satellites,
identified as 21L, 22L, and 23L, and Kosmos 2499 into roughly 1,500 km x 82.5 deg orbits.

The first Briz KM burn began about five minutes after liftoff and lasted for about 9.5
minutes to insert the vehicle into an elliptical parking orbit. The second, circulization
burn began about 1.5 hours after liftoff near apogee and lasted for less than one minute.
Spacecraft separation occurred shortly thereafter.

It was the year's first Rokot launch and the year's 20th orbital launch world-wide.

China Launches Navsat

China launched a new type of navigation satellite into orbit, using a new type of upper
stage, from Xichang Satellite Launch Center in southwest Sichuan Province on March 30,
2015. A Chang Zheng 3C topped by a new hypergolic bipropellant space maneuvering stage
named Yuanzheng 1 (YZ-1) lifted off from Pad 2 at 13:52 UTC with Beidou 17 (also
identified as Beidou 3I-1).

It was China's first orbital launch of 2015 and the world's seventh orbital launch in five
days.

India Launches Navsat

PSLV-C27, India's 29th Polar Satellite Launch Vehicle, launched IRNSS-1D, the fourth
Indian Regional Navigation Satellite System satellite, into orbit from Sriharikota on
March 28, 2015. The 320 tonne, 4.5 stage rocket, flying in the "XL"
configuration with four stretched strap-on solid motors, lifted off from the Second Launch
Pad at 11:49 UTC.

The first three core stages fired in succession during the first 10 minutes 19 seconds of
the mission, boosting the vehicle into a temporary parking orbit. After an 8 minute 29
second coast, the fourth stage fired to boost the vehicle into a 284 km x 20,650 km x 19.2
deg sub synchronous transfer orbit. IRNSS-1D, which weighed 1,425 kg at launch, will
subsequently fire its Liquid Apogee Motor several times to lift itself into a 35,786 km x
30.5 deg inclined geosynchronous orbit.

A Soyuz 2-1b with a Fregat upper stage launched a pair of European Galileo navigation
satellites into orbit from Kourou Space Center on March 27, 2015. Flying the VS11
mission for Arianespace, the 3.5 stage rocket lifted off from the ELS pad at 21:46 UTC to
begin a planned 3 hour 47 minute mission designed to loft the two 733 kg satellites into
23,522 km x 55.04 deg circular orbits.

Fregat performed two burns during the mission. The first, completed 24 minutes
after liftoff, placed the vehicle into an elliptical orbit with a 23,500 km apogee.
The second, which began about 3 hours 39 minutes into the flight, aimed the stage and
spacecraft toward their insertion orbit.

It was the first Galileo launch since a Fregat failure placed two Galileo satellites
into an improper orbit on August 22, 2014. Investigation found that the stage
attitude control system was compromised by thruster propellant lines that were frozen by
adjacent helium lines during the long coast to apogee. Galileo missions introduce a
longer coast than has been used during prior Fregat missions, exposing a previously
unsuspected configuration control issue in the routing of propellant lines by stage
manufacturer NPO Lavochkin.

OHB-System and SSTL built the satellite bus and payload, respectfully, for the seventh
and eighth Galileo satellites. After the 2014 failure, these will become the first
two Full Operational Capability" satellites of a planned 22 satellite
constellation.

ISS Crew Launch

A 2.5-stage Soyuz FG rocket lofted the Soyuz TMA-16M spacecraft with three International
Space Station crewmembers from Baikonur Cosmodrome on March 27, 2015. Onboard were Russian
Cosmonauts Gennady Padalka and Mikail Kornienko, and NASA astronaut Scott Kelly. Kornienko
and Kelly are expected to spend an entire year on ISS.

Liftoff from Area 1 Pad 5 took place at 19:43 UTC, starting a now-standard
"fast-track" six-hour flight to the station. It was the year's first
crewed launch to orbit.

The 22nd Ukrainian-Russian Dnepr launch vehicle, a converted R-36 series ICBM, placed
Kompsat 3A into orbit from Russia's Dombarovsky launch site near Yasny in southwest Russia
on March 25, 2015. Liftoff from an underground silo at Site 370/13 took place at 22:08
UTC.

Korea Aerospace Research Institute developed Kompsat 3A. It will perform an imaging
mission from its position in sun synchronous low earth orbit.

The launch was the 15th consecutive Dnepr success. International Space Company (ISC)
Kosmotras, a Ukrainian/Russian joint venture, handled the launch services portion of the
mission while Russian Missile Forces crews performed the launch. Dnepr's long-term future
is in doubt due to the now one-year-long conflict in Ukraine.

Delta
4 Launches GPS 2F-9

A Delta 4 rocket orbited GPS 2F-9 from foggy Cape Canaveral, Florida on March 25, 2015.
The 2.5 stage Delta 4M+4,2, with two GEM-60 solid boosters and a four meter diameter upper
stage and payload fairing, lifted off from Space Launch Complex 37B at 18:36 UTC. It was
the sixth and final GPS 2F series launch performed by a Delta 4. Atlas 5 will launch the
final three GPS 2F satellites during coming months to complete the upgraded navigation
satellite constellation.

Delta 4's Delta Cryogenic Second Stage (DCSS) performed two burns during a 3.25 hour
mission to lift the 1.63 tonne satellite into a 20,459 km x 55 deg circular orbit. The
first, long burn lifted the vehicle into a 197 x 20,431 km transfer orbit on a northeast
heading. RL10B-2 cutoff came more than 15.5 minutes after liftoff. After a 3 hour
coast, DCSS peformed a short apogee burn to circularize the orbit.

It was first Delta 4 launch of 2015, the 21st Delta 4 Medium-series launch, and the 29th
flight by any type of Delta 4. It was also the last launch using a standard RS-68
engine. All future launches will use the improved RS-68A type.

ULA CEO Tory Bruno's recent announcement of plans to shelve the Delta 4 Medium launch
vehicle after 2017 mean that only about eight more examples of the single-core vehicle are
currently expected to fly. As many as five more Delta 4 Heavy launch vehicles are still on
the manifest with launches planned into at least 2020.

Proton Orbits
Express AM7

Russia's Proton orbited the Express AM7 communications satellite from Baikonur Cosmodrome
on March 18, 2015. The 705 tonne, four-stage rocket lifted off from Site 200 Pad 39 at
22:05 UTC to begin a 9 hour 13 minute mission that included five burns by the Briz M upper
stage.

Briz M fired first, just after the three Proton stages completed their burns, to place
itself into a 182 km x 52.56 deg parking orbit. It fired three more times during the first
3.8 hours and two orbits of the mission to place itself into a 430 x 35,806 km x 49.1 deg
geosynchronous transfer orbit. After a 5.4 hour coast to first apogee, Briz M fired a
fifth time to raise the perigee and reduce inclination. Express AM7 separated into a
targeted 5,410 x 35,786 km x 20 deg transfer orbit.

Express AM7 is a 5.712 tonne Eurostar E3000 series satellite with 24 C-band, 36 Ku-band
and 2 L-band transponders. It will provide digital broadcasting services, government
communications services, and Internet based services across Russia.

A 543 second long RL-10 burn put the Centaur second stage into a 167 x 591 km x 28.72
degree parking orbit. After a 59 minute coast, the stage fired again for 342 seconds to
boost itself into a 580 x 70,279 km x 28.779 degree insertion orbit.

MMS consisted of four 1,360 kg spacecraft that were stacked atop one another during launch
in an extended payload fairing. The satellites, which separated from Centaur sequentially,
will fly in formation to study how magnetic fields around Earth connect and disconnect in
a process called magnetic reconnection.

It was the 2nd Atlas 5 launch of 2015 and the 53rd overall. It was also the 5th orbital
launch of the year from Cape Canaveral.

Falcon 9 Orbits
Ion Engine Satellite Pair

Falcon 9 No. 16 During Final Minutes of Countdown

The 16th SpaceX Falcon 9 launch vehicle, and the 11th
Falcon 9 v1.1 variant, launched two landmark communications satellites into orbit from
Cape Canaveral on March 2, 2015. Liftoff from Cape Canaveral SLC 40 took place at 03:50
UTC. ABS-3A and Eutelsat 115 West B, the first two all-ion-engine powered Boeing HS-702SP
satellites, were stacked atop one another inside the 5.2 meter diameter payload fairing.

The first stage was not equipped with landing legs or grid fins for a landing attempt due
to the requirements of the mission. The first stage fired for 2 min 56 seconds before
separating. After a 10 second unpowered interval, the second stage started its Merlin 1D
Vacuum engine for a 5 min 44 second burn that boosted the vehicle into a 174 x 953 km x
28.19 deg parking orbit. The stage coasted for 16 min 52 seconds before reigniting for a
59 second burn that boosted the stage and payloads toward a reportedly targeted
supersynchronous transfer orbit of 408 x 63,928 km x 24.83 deg. The satellites
separated in sequence during the subsequent nine minutes and were subsequently tracked in
roughly 400 x 63,300 to 63,400 km x 24.8 deg orbits that exceeded customer requirements.
They will gradually maneuver themselves to geostationary orbit, a process that will
take at least eight months due to the low thrust provided by the ion engines.

ABS-3A stacked atop Eutelsat 115 West B During
Payload Processing

By dispensing with standard liquid monomethyl hydrazine
propellants in favor of highly efficient xenon-ion propulsion system (XIPS), Boeing
developed satellites that could weigh substantially less. Each satellite has at least four
25 cm diameter XIPS, each producing about 8.2 grams thrust at an average ISP of 3,420
seconds.

ABS-3A weighed 1.954 tonnes and Eutelsat 115 West B weighed 2.205 tonnes, about half the
weight of a standard satellite of equal capability. The Eutelsat satellite weighed more
than ABS-3A because it was the lower of the two satellites and was designed to support the
weight of ABS-3A. This arrangement allowed for a standard Falcon 9 payload fairing
and payload attach fitting to be used.

The total 4.159 tonne payload mass was the heaviest boosted to a supersynchronous transfer
orbit by Falcon 9 to date. The rocket performed a static test firing on the pad on
February 25 with no payloads or payload fairing attached.

Bars-M is the first of its type. It will maneuver itself to a likely 700 km sun
synchronous orbit. There it will capture wide-area digital images for mapping and other
purposes. TssKB Progress developed Bars-M, which uses a Karat camera made by the Leningrad
Optical-Mechanical Association (LOMA).

It was the fifth Soyuz 2-1a launch to orbit without an upper stage, not including a 2004
suborbital test flight. An additional 15 Soyuz 2-1a vehicles have flown with Fregat upper
stages.

Soyuz
Orbits Progress

A Soyuz U boosted Russia's Progress M-26M unmanned cargo spacecraft into orbit bound for
the International Space Station from Baikonur Cosmodrome on February 17, 2015. The 2.5
stage kerosene fueled rocket lifted off from Area 1 Pad 5 at 11:00 UTC. Progress M-26M
docked with the station 5 hours 57 minutes later.

Progress weighed 7.287 tonnes at liftoff. It entered an initial 194 x 247 km x 51.65 deg
orbit, from which it quickly maneuvered to rendezvous with ISS. The ship carried 2.8
tonnes of dry cargo, food, rocket propellant, water and oxygen to the space station.

It was the year's first R-7 launch, and the first Soyuz
U launch since July, 2014 as the long-running type is beginning to be phased out in favor
of Soyuz 2.1.

The first stage shut down its nine Merlin 1D engines about 164 seconds after liftoff and
the second stage Merlin Vacuum engine began a 5 minute 44 second burn to boost the vehicle
into a parking orbit. After coasting across the Atlantic Ocean, the second stage reignited
at the 30 minute 9 second mark to begin a 58 second burn aimed to boost DSCVR into a
highly elliptical earth orbit. The target orbit was 187 x 1,241,000 km x 37 degrees. The
achieved orbit was 187 x 1,371,156 km x 37 degrees.

DSCOVR is a 570 kg satellite that was originally built by Lockheed Martin during the
1990s. It will move itself into a Lissajous orbit around the Sun-Earth L1 Lagrangian
point, 1,500,000 km from Earth in line with the Sun. There it will monitor the solar wind
and provide images of the fully-illuminated side of the Earth. The spacecraft will take
110 days to reach its final L1 orbit.

It was the third launch attempt for DSCOVR. A February 8 attempt was scrubbed with a
little more than 2 minutes remaining in the count due to a range tracking issue. A
February 10 attempt was scrubbed due to excessive high altitude winds. The rocket
performed its static fire test at SLC 40 on January 31, 2015 during the day's second
attempt.

After the first stage separated, it performed a reentry burn followed by a terminal
landing burn, but a second attempt to land on a converted barge had to be abandoned due to
high seas. The landing attempt would have been more than 400 km downrange. An
initial boost-back burn performed during previous recovery missions was not performed due
to the need to assign propellant to the DSCOVR ascent.

It was the second Falcon 9 launch of 2015.

Vega Launches
Space Plane

Europe's solid-fuel Vega rocket launched a small atmospheric reentry demonstrator space
plane on a 100 minute suborbital flight from Kourou on February 11, 2015. The flight
tested heat shield technology, hypersonic aerodynamics, and other systems during the
vehicle's reentry before a Pacific Ocean splashdown beneath a 30 meter diameter parachute.

Vega lifted off from the ZLV pad at 13:40 UTC to begin the VV04 mission. The rocket's
solid-fueled first three stages burned in sequence during the first 6 minutes 37 seconds
of the mission, with the payload fairing separating after the second stage burn, about
four minutes into the flight. The AVUM upper stage with its payload then performed a 6
minute burn using its KB Yuzhnoye RD-869 derived UDMH/N2O4 engine before separating from
the payload 17 minutes 59 seconds after liftoff.

The 1.845 tonne space plane, identified as the Intermediate Experimental Vehicle (IXV) was
was released from Vega at a 340 km altitude into a 76 x 416 km x 5.4 deg orbit. IXV
climbed to apogee before falling back into the atmosphere to begin reentry at 7.5 km/sec.
IXV was steered by four hydrazine thrusters augmented in the atmosphere by two
rear-mounted aerodynanic flaps. During the final minutes of the flight, IXV deployed
a supersonic parachute, followed by a drogue and the main chute. Splashdown occurred at
about 15:19 UTC west of the Galapagos Islands.

After spacecraft separation, the AVUM performed two
burns. The first may have accelerated the stage briefly into orbit. The second
likely deorbited the stage into the Atlantic Ocean.

The 5 meter long, 2.2 meter diameter IXV was built by Thales Alenia Space as prime
contractor on behalf of the European Space Agency (ESA). Italy provided most of the
funding for the mission.

Vega had stood stacked at ZLV for months after a planned November 2014 launch date was
cancelled just before final launch preparations due to European Space Agency and French
space agency, CNES, concerns about the planned flight path out of Kourou. It was the
first non-polar flight for Vega. On previous missions, Vega had flown north from its
launch pad. This was the first flight aimed toward the northeast. The delay "allowed
time for additional analyses of the flight trajectory", according to Arianespace.

Iran
Orbits Satellite

Iran achieved its fourth successful orbital launch on February 2, 2015, when a Safir 1B
lofted a 50 kg satellite named "Fajr" ("Dawn") into low earth orbit
from a base in the Dasht-e-Kavir desert southeast of Semnan. Iran did not announce
the liftoff time, which was estimated by outsiders to have been approximately 08:50 UTC.

Fajr is Irans fourth satellite.
Previous successful missions, all performed by Safir boosters, took place in 2009, 2011
and 2012. Two unannounced, suspected launch failures may have occurred during 2012.

Safir is derived from Iran's Shahab 3 ballistic missile.

Proton Orbits
Inmarsat 5F2

A Khrunichev Proton M/Briz M boosted Inmarsat 5F2 to supersynchronous transfer orbit from
Baikonur Cosmodrome on February 1, 2015. Liftoff took place began from Area 200 Pad 39 at
21:37 UTC.

The Briz M upper stage performed five burns during the more than 15.5 hour mission. The
first burn placed the vehicle into a 173 km x 51.5 deg parking orbit during the initial
ascent. The second burn, starting about 1 hour 50 minutes after liftoff, raised the orbit
to 295 x 6,000 km x 51.0 deg. The third and fourth burns took place sequentially beginning
at T+4 hours 23 minutes, with the APT drop tank jettisonned between burns. The vehicle was
in a 475 x 65,044 km x 50.5 deg transfer orbit after the fourth burn, with a 10 hour coast
to apogee for the fifth burn, which aimed Inmarsat 5F2 toward a 4,341 x 65,000 km x 26.75
deg delivery orbit.

Boeing Satellite Systems built the 6.07 tonne BSS-702HP series satellite for Inmarsat. It
is equipped with 89 Ka-band beams for mobile broadband communications. It also has a xenon
ion propulsion system. Inmarsat 5F2 will be positioned at 55 deg West.

SMAP was built by the Jet Propulsion Laboratory (JPL). Goddard Space Flight Center manages
the program. The satellite will measure global soil moisture and freeze/thaw states to
assess global water resources.

Delta lifted off on 227 tonnes of combined sea-level thrust from its three GEMs and its
90.72 tonne thrust Rocketdyne RS-27A LOX/RP engine. The three solid motors burned out 64.5
seconds after liftoff and jettisonned at the 99 second mark. The RS-27A first stage engine
shut down at 261.8 seconds. The second stage separated at 268 seconds and its 4.45 tonne
thrust Aerojet AJ10-118K pressure fed hypergolic engine ignited eight seconds later to
begin the first of two burns. Fairing jettison occurred at 295 seconds. The first second
stage burn ended at 643.6 seconds, leaving Delta and SMAP in a 176 x 701 km x 98.1 deg
parking orbit. After coasting over Antarctica and the southern Indian Ocean, the second
stage reignited over Madagascar at 3098 seconds and cut off at 3110.1 seconds. SMAP
separated at 3410.5 seconds, or 56 minutes 50.6 seconds.

About 48 minutes after
SMAP separation the second stage was to perform a brief third burn before three PPOD
microsatellites were scheduled to be released. The second stage would perform a
fourth and final burn at the end of the mission.

The rocket flew as Delta 370, but it was only the 339th Delta with a Thor-derived first
stage and a hypergolic second stage. An additional three Delta 3 rockets flew with liquid
hydrogen second stages. The remaining 28 "Deltas" were RS-68 powered Delta 4
rockets. "Delta 370" was the 721st Thor family launch and the 608th Thor family
orbital attempt. It was also the 98th consecutive Delta 2 success.

Atlas
5 Launches MUOS 3

The most powerful Atlas 5 variant, an Atlas 5-551 with five strap on solid motors and a
five meter diameter payload fairing, lofted the third of five planned U.S. Navy Mobile
User Objective System (MUOS 3) communications satellites into orbit from Cape Canaveral,
Florida on January 21, 2015. Liftoff from Space Launch Complex 41 took place at at 01:04
UTC. The 568 tonne rocket's Centaur upper stage fired its RL10C-1 engine three times
during a nearly 3 hour mission to lift MUOS 3 toward a planned 3,817 x 35,787 km x 19.11
deg geosynchronous transfer orbit.

At 6.74 tonnes, the MUOS satellites are the heaviest known payloads launched by an Atlas
5, though the mass of several secret national security payloads launched by Atlas 5 have
never been published. Lockheed Martin Space Systems is the MUOS prime contractor. The
satellites provide narrowband tactical voice and data communications and are equipped with
a 14-meter diameter reflecting mesh antenna to provide links to ground-based users.

It was the 52nd Atlas 5 launch and the fifth 551 variant. It was also the second flight of
an RL10C-1 engine. The vehicle's second stage was the 200th Centaur flown atop a first
stage named "Atlas", though only 142 of those flew atop an original
stange-and-a-half ICBM-derived Atlas.

Falcon 9 Orbits
Dragon CRS-5

SpaceX's ninth Falcon 9 v1.1 rocket successfully orbited another of the company's Dragon
spacecraft on the CRS-5 (Cargo Resupply Services) mission from Cape Canaveral, Florida on
January 10, 2015. Rising on nearly 590 tonnes of thrust produced by its nine first stage
Merlin 1D engines, the 63.4 meter tall two-stage rocket lifted off at from Space Launch
Complex 40 at 09:47 UTC and steered on a northeastward track. The first stage shut down
its nine Merlin 1D engines about 157 seconds after liftoff and the second stage Merlin
Vacuum engine began a roughly 7 minute burn to boost the vehicle into a 206 x 353 km x
51.64 degree orbit.

Dragon carried 2.317 tonnes of cargo for International
Space Station Expeditions 42 and 43. The spacecraft likely weighed as much as 9.7 tonnes
at liftoff, including cargo. One unpressurized payload carried in Dragon's trunk was NASA
Goddard's Cloud-Aerosol Transport System (CATS), a laser remote sensing experiment
designed to measure clouds and aerosols in the atmosphere. It also carried an IMAX camera
and tools for future spacewalks to prepare the station for the installation of the new
international docking adapters.

After about four weeks at ISS, Dragon will return to a Pacific Ocean splashdown loaded
with more than 1.633 tonnes of return cargo, packaging materials, and trash.

It was the second launch attempt for CRS-5. A January 6 attempt was scrubbed 1 minute 21
seconds before the planned liftoff because of a second stage engine thrust vector control
actuator issue. SpaceX said that engineers had "observed drift on one of the two
thrust vector actuators (Elon Musk identified it as the "Z actuator") on the
second stage that would likely have caused an automatic abort". A similar problem had
appeared during the rocket's initial hot fire test countdown at SLC 40 on December 17,
2014 but engineers had thought the problem subsequently solved.

That initial hot fire test was itself aborted after ignition due to a valve problem,
causing the planned December 20 launch date to slip to January 6. A second hot fire test
attempt was successful on December 19, 2014.

After the first stage separated, it performed another in a continuing series of SpaceX
stage recovery experiments. This time, for the first time, a landing was attempted on a
converted barge, parked more than 350 km downrange, that was equipped with a flat top
landing platform and position-holding capabilities. Also, for the first time, four
grid-fins attached to the interstage were used to help steer the stage toward a precise
landing spot. The stage reignited three of its engines to perform an initial boost-back
burn to shorten its range. Then, as it fell through the upper atmosphere, it fired its
engines a second time to reduce reentry velocity.

A third single-engine landing burn took place during the final moments of the descent,
designed to set the stage safely down on four landing legs that were to deploy just before
landing. The stage apparently steered itself to the barge and attempted to land, but it
crashed, or landed hard, on the barge and was destroyed. The barge itself remained afloat,
but stage recovery equipment aboard the barge was destroyed. SpaceX head Elon Musk
announced that the grid fins had worked during the hypersonic to subsonic velocity phase,
but that they exhausted their hydraulic fluid supply shortly
before the landing, which may have contributed to the crash.

It was the first orbital launch of 2015 and the 14th Falcon 9 launch.

ULA/Blue Origin to Develop Powerful New Engine

BE-4 Model at Press
Conference

On September 17, 2014, United Launch Alliance and Blue Origin, a privately held company
owned by Amazon.com founder Jeff Bezos, announced that they were teaming to jointly fund
development of Blue Origin's new BE-4 rocket engine. The development effort would last
four years, with full-scale testing in 2016 and first flight in 2019. The new engine would
be available for use by both companies.

Blue Origin has been working on BE-4 development for three years, with component testing
underway at the company's test site near Van Horn, Texas and in facilities near Kent,
Washington. Completed testing has included subscale oxygen-rich preburner development and
staged combustion testing of the preburner and main injector assembly. Testing of the
turbopumps and main valves is the next major step. A large new test facility was completed
in May, 2014 in Texas to support full-scale engine testing.

BE-4 should operate at a higher specific impulse than the Atlas 5 RD-180, but not as high
as Delta 4's RS-68. The engine could be heavier than RD-180, and the less dense propellant
would force use of bigger, heavier tanks than those used by Atlas 5, but BE-4s higher
thrust compared to RD-180 would help offset those factors.

ULA noted that BE-4 is not a direct replacement for RD-180, but that "two BE-4s are
expected to provide the engine thrust for the next generation ULA vehicles". The
company said that the "next generation vehicles" would "maintain the key
heritage components of ULAs Atlas and Delta rockets", including the strap-on
solid boosters, and said that details would be announced at a later date.

NASA Awards Commercial Crew to
Boeing, SpaceX

CST-100 Approaching ISS

On September 16, 2014, NASA awarded commercial crew contracts to Boeing and SpaceX.
Boeing was alloted $4.2 billion to develop and fly CST-100. SpaceX won $2.6 billion
to develop its Dragon V2. Although the awards differed in value, both companies responded
to identical requirements. Both will develop and certify their spacecraft and launch
systems, will perform a single crewed demonstration mission, possibly before the end of
2017, and both then will fly two to six missions to the International Space Station,
carrying four astronauts during each flight. Both spacecraft will be designed to stay at
ISS for up to 210 days to provide a lifeboat function.

The announcement left out Sierra Nevada Corporation's Dream Chaser, a lifting body design
that would have glided to runway landings.

CST-100, a 4.56 meter diameter, 5.03 meter tall spacecraft, was expected to be launched by
United Launch Alliance's Atlas 5 rocket. The spacecraft will use four Aerojet Rocketdyne
RS-88 launch abort engines mounted in a pusher configuration on the aft end of a small
cylindrical service module to provide emergency aborts. The engines will burn NTO and
Hydrazine to together create about 72 tonnes of thrust. Aerojet Rocketdyne will also
provide orbital maneuvering and attitude control thrusters for the spacecraft.

Dragon V2

An Atlas 5-422 version fitted with two strap on solid motors and a Centaur second stage
powered by two RL-10 engines was a likely CST-100 launch vehicle. Development and
certification of the two-engine Centaur would be required. Launches would take place from
Cape Canaveral Space Launch Complex 41.

Dragon V2, a 3.7 meter diameter, 6.7 meter tall spacecraft, will be launched by a SpaceX
Falcon 9 v1.1. The launch site would be either SLC 40 at Cape Canaveral or LC 39A at
Kennedy Space Center, which SpaceX is currently refurbishing for Falcon Heavy.

One reason for the contract price difference is likely that SpaceX has a head start on
Boeing. SpaceX is already launching Dragon cargo missions to ISS. Dragon V2 will be built
in the same factory and launched by the same, already proven rocket as Dragon. Boeing
still has to have its launch vehicle developed and still has to outfit a production
facility for its spacecraft. The company plans to build and process CST-100 in a former
Orbiter Maintenance Facility building at KSC.